I think they came into contact with that planet because of the Ingress interference. But they didn't care about what we did to the slavers. The Ingress was all they cared about.

I know because I tried to appeal for the people the intermediaries took. Their response said as much. It doesn't matter what the slavery had done to people. All they cared about was that the Ingress had been touched.

[That impersonal treatment had been his first clue, the source of doubts for him.]